· DBNull使用技巧易动工作室 EPower2002VB.NET的变化之一是将VB6中能用的IsNull和IsEmpty函数删除了,而提供另一种方式来确定变量是否被初始化,即IsDBNull()方法.
IsDBNull()方法接受一个对象作为它的参数,并返回一个布尔值指示变量是否被初始化.
Dim strMyName as String
if Not isDBNull(strMyName)...
· Working with the RAPI Class
为了简化RAPI类的操作,我将添加一个using声明到示例程序的C#版本,或添加一个Imports声明到VB.NET中,示例如下:[VC#.NET]
using OpenNETCF.Desktop.Communication;
[VB.NET]
Imports OpenNETCF.Desktop.Communication
另外,我将添加一个单独的module-level变量,my...
· Moving Files on a Device
也许你会遇到需要在设备上移动或者重命名一个文件的情况。例如,你也许想在拷贝一个新版本的文件到设备上之前先为配置文件做一个备份。该功能的演示界面如图2。Figure 2. The Move File tab of the RAPI demo programOpenNETCF.Desktop.Communication命名空间RAPI类提供 ...
· 适用于:Microsoft® Windows® .NET Server 2003 Enterprise Edition Microsoft Windows .NET Server 2003 Datacenter Edition Microsoft 群集服务摘要:了解如何在群集环境中对应用程序轻松执行性能检查,而无需更改应用程序代码。本文着重介绍三个支持群集的 Microsoft 服务器技 ...
· 环境:win2000 server 、DOTNET beta2本程序旨在练习,请朋友们多指教using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;namespace SohoContral
{
/// <summary>
/// 定义平面格式的按扭...
· SET [variable=[string]]variable 指定环境变量名称。string 指定要指派给变量的一系列字符。********************************
仅键入 SET 而不加参数,可以显示当前的环境变量。********************************
如果命令扩展名被启用,SET 会如下改变:可仅用一个变量激活 SET 命令,等号或...
· 下面是实现上面结果的程序源代码:using System ;
using System.Drawing ;
using System.Collections ;
using System.ComponentModel ;
using System.Windows.Forms ;
using System.Data ;
namespace DynamicControls
{
public class Form1 : Form
{
private Button btnAdd ;
private System.Compo...
· //---------------------------------------
// form1.cs
//----------------------------------------
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;namespace FormConmunicate
{
/// <su...
· Windows Management Instrumentation (WMI) is a very powerful mechanism for getting information about your system. Not only the local system but also other systems on the network should you desire. To start using the WMI classes you will need to add a reference to System.Manage...
· Detecting OS Version using Environment ClassIn Win32 SDK, we have an API GetVersionEx that returns the information in OSVERSIONINFO structure. And then we can look at the values of various members of structures to decide what version of operating system we are running on. To ...